Relative Intensity of Physical Activity and Risk of Coronary Heart Disease

Abstract

Background-Current recommendations prescribe at least moderate-intensity physical activity, requiring Ն3 METs (metabolic equivalents) for Ն30 minutes almost daily, generating Ϸ1000 kcal/wk. Defining intensity using an absolute scale in METs may be limited because it neglects variations in physical fitness: an activity requiring a particular MET value commands greater physical effort among less fit than more fit persons. It is unknown whether moderate-intensity exercise, relative to an individual's capacity, is associated with reduced coronary heart disease (CHD) rates. Methods and Results-We followed 7337 men (mean age, 66 years) from 1988 to 1995. At baseline, men reported their actual activities and, using the Borg Scale, the perceived level of exertion when exercising (relative intensity). During follow-up, 551 men developed CHD. After multivariate adjustment, the relative risks of CHD among men who perceived their exercise exertion as "moderate," "somewhat strong," and "strong" or more intense were 0.86 (95% confidence interval, 0.66 to 1.13), 0.69 (0.51 to 0.94), and 0.72 (0.52 to 1.00), respectively (P trend ϭ0.02), compared with "weak" or less intense. This inverse association extended to men not fulfilling current recommendations, ie, expending Ͻ1000 kcal/wk in physical activity or not engaging in activities of Ն3 METs (P trend ϭ0.03 and 0.007, respectively). Conclusions-There is an inverse association between relative intensity of physical activity (an individual's perceived level of exertion) and risk of CHD, even among men not satisfying current activity recommendations. Recommendations for "moderate"-intensity physical activity may need to consider individual fitness levels instead of globally prescribing activities of Ն3

Long-term combined beneficial effects of physical training and metabolic treatment on atherosclerosis in hypercholesterolemic mice

“…Moderate exercise ameliorates endothelial function and reduces cardiovascular risk (6)(7)(8)(9)(10)(11)(12)(13)(14). Several highly plausible protective mechanisms have been postulated, including decreased myocardial oxygen demand, increased myocardial oxygen supply, reduced propensity toward ventricular arrhythmias, reduced platelet aggregation, improved lipid profile, and increased plasma fibrinolytic activity (4)(5)(6)(7)(8).…”

“…The higher respiration rate during severe physical exercise leads to the generation of more free radicals than the endogenous antioxidant systems can scavenge (9), whereas moderate intensity aerobic exercise enhances endothelium dependent vasodilation in humans (10), and attenuates exercise-induced peroxidation (11) and cardiovascular mortality (12) in the elderly. Moreover, there is an inverse association between intensity of physical activity and the risk of coronary heart disease events (13). A metaanalysis of 51 controlled trials evaluated the effects of exercise-based cardiac rehabilitation on cardiac events (14), demonstrating that total mortality decreases 27% and cardiac mortality decreases 31%.…”

Physical Activity and Cardiovascular Disease: Directions for Future Research

“…However, despite extensive research in this field there are crucial gaps in our knowledge. This paper discusses future research directions including population subgroup-specific exercise doses, research in under represented populations, the role of cardiorespiratory fitness in predicting CVD risk, and novel biological mechanisms that might mediate the inverse association between physical activity and CVD risk.Regular physical activity is widely accepted as playing a crucial role in cardiovascular disease (CVD) prevention [1][2][3][4][5][6]. Current physical activity recommendations for the general population advocate the accumulation of at least 30 minutes of moderate intensity physical activity on five or more days a week or vigorous activity at least three times per week [7].…”

“…Although the evidence on the health benefits of walking, cycling, or stair-climbing is compelling, the degree of protection conferred from intense domestic physical activity is less clear and future research must address this issue. Several large scale prospective cohort studies in men suggest that vigorous activity is more beneficial for protection against CVD [3,4]. For example, in the Health Professional's follow up study, men who ran for an hour or more per week had a * Address correspondence to this author at the Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, UK; Tel: (44) 20 7679 5969, Fax: (44) 20 7916 8542, E-mail: m.hamer@ucl.ac.uk 42% CVD risk reduction compared with 18% lowered risk in men that only walked briskly for half an hour per day [4].…”

“…Regular physical activity is widely accepted as playing a crucial role in cardiovascular disease (CVD) prevention [1][2][3][4][5][6]. Current physical activity recommendations for the general population advocate the accumulation of at least 30 minutes of moderate intensity physical activity on five or more days a week or vigorous activity at least three times per week [7].…”